FAQ & Troubleshooting

Does Cascade Hydro work offline?

Mostly, yes. Three things need an internet connection:

• Importing an ECCC station record from the Map tab,
• the background map tiles, and
• automatic updates.

Everything else runs offline. You can load a precipitation record from a local CSV or Excel file via the Data tab's Open File…, and you can save and reopen a complete .chyd session without any connection. Once a record is loaded — whether from ECCC or a file — the full analysis (diagnostics, fitting, IDF curves, design storms) is local.

For exactly which services are contacted and what is cached locally, see Data sources.

How is the ecozone chosen, and what happens if it can't be determined?

The sub-daily / IDF depth ratios are keyed to ecozone (climatic region), not province, because the sub-hourly-to-daily depth ratio follows storm regime (convective vs. synoptic) rather than administrative boundaries.

The ecozone is resolved from the active location's latitude and longitude by point-in-polygon lookup against the national ecozone boundaries, or you can set it manually. When a location is outside the available coverage — or none has been set — the tool falls back to a province-level convenience table, and then to a national-average table. Fallback values are flagged as planning-level confidence rather than presented as region-specific. Set a project location on the Map tab to get the most specific ratios; the Data tab warns when no ecozone is selected.

See the Sub-daily ratios overview for how the region is chosen and what the confidence levels mean.

Why are sub-daily estimates from daily data "approximate"?

A daily record contains one value per day, so it carries no direct information about sub-daily intensities (the 5-minute, 1-hour, etc. maxima that IDF curves need). When only daily data is available, the tool estimates those shorter durations by scaling the 24-hour depth by the regional ecozone ratio — the lowest-preference of its estimation tiers:

1. Observed sub-daily annual maxima, where the record contains them.
2. Fitted-curve interpolation across observed durations.
3. Ratio scaling of the 24-hour depth (daily-only records).

The applied tier is disclosed in the IDF report. Tier 3 is a regional approximation, not a measurement, so sub-daily values from daily data should be treated as planning-level. Where sub-daily observations exist, the tool uses them and never applies the ratios. The validation page quantifies how the ratio-based sub-daily curves compare against a published ECCC product.

A year (or a value) was excluded from my analysis — why?

Two independent screens can remove data before fitting, and both are shown in the controls of the tab you are on:

• Completeness screening drops calendar years that are too incomplete (a maximum from a partial year is biased low).
• Outlier screening flags extreme values by the selected statistical test.

The Analysis and IDF tabs screen independently, and screening is off by default — enabling it is a disclosed choice. Use Compare impact on either tab to see the result with and without screening side by side, including exactly which years and values changed.

See the Methods overview for the screening rules and their sources.

How do updates work?

Cascade Hydro checks for updates on launch and downloads them quietly in the background. When one is ready, a banner appears above the tabs offering Restart now or Later (Later applies the update on the next launch). You never need to download an installer again after the first install. See Automatic updates.

Where do I see the installed version and release notes?

Open Settings → About. It shows the running version and the changelog for each release. A summary also lives on the Release notes page.

The map is blank — is something wrong?

The map needs an internet connection for its tiles. If it stays blank, check your connection. Note that a loaded analysis does not depend on the map; once your location or station is set, the rest of the workflow is local.